I hope nobody minds, I don't mean to threadjack. Heres some pictures of other kids who are being raised with motorcycles as a regular part of their lives.
This is my son Colin (two years old at the time) sitting on his big sister's motorcycle, which was her 6th Birthday present this May. He's ridden it a bit, but is not confident with it yet. He's been riding a bicycle without training wheels for months now, this kid is amazing.
This is Cailan, my daughter riding a motorcycle by herself for the first time.
I frequently take the kids around the neighborhood on my bike. Cailan actually operates the throttle on my SV1000S for all but the stopping and pulling away from a stop. I cover the clutch the whole time, but have never had to pull it on her, she's hasn't gotten greedy yet.
Colin has to stretch out a lot to reach the handlebars, but I see the best grins on his face when I angle the mirror to catch them.
This is actually my baby half-brother. He's about nine months older than my daughter. This was his first time on a motorcycle I let him crack the throttle a bit in neutral.
I think it was a positive experience.
I think the most important part of having kids around motorcycles is to make sure that their experiences are good ones. As a result I don't push them to ride or to try stuff they're not comfortabe with, I just try to get them to have fun. So far its going very well, Cailan's confidence on the bike has grown a lot. It's looking like she'll be upgrading from the Razor electric bike to a CRF50 or the like for Christmas.